1. Field of the Invention
This invention relates to an image reader and a printing system, and more particularly to a printing control executed responsive to the property of an image.
2. Description of the Related Arts
As the image reader, a digital copying machine, a scanner, a composite device which is composed of these devices or the like is considered. Such an image reader is provided with an automatic original transfer mechanism which is generally called as an automatic document feeder (ADF). With the ADF, an original is supplied onto a platen one by one out of plural originals which are set in the ADF, while the original from which the image is read is discharged one by one.
Among digital copying machines, there is a type of digital copying machine which automatically recognizes information on the property of the original (hereinafter called as `original information`) based on a prescanned image obtained by a prescanning, and responsive to such original information, parameters necessary at the time of main scanning or parameters necessary at the time of processing the image read by main scanning are set. Using such a function, various information on, for example, the color, the size, the density, the contrast and the like of the original can be obtained. In the conventional device, however, the fact is that such a function is not effectively used in other applications.
Conventionally, for example, in executing an automatic copying of plural originals by means of the above-mentioned digital copying machine, it is impossible to automatically exclude a specific original out of plural originals from objects to be copied. Accordingly, in case an original which a user does not wish copying thereof is present among a large number of originals, for example, the user must take out such an original in advance before copying and insert the original to the same position after copying, or all originals must be copied first and then unnecessary copied papers must be removed from all the copied papers thus bringing about a cumbersome copying operation.
In view of the above-mentioned problems, Japanese laid-open patent publication Hei 5-56220 discloses a device which executes prescanning of each original at the time of executing copying of plural originals set in the ADF and if it is judged the original is a white paper original, an alarm display is performed so as to prevent copying thereof. In such a device, however, it is necessary to give a direction always manually to perform the alarm display.
Japanese laid-open patent publication Hei 9-102853 discloses a device in which a user gives a direction and sets whether main scanning should be executed or not based on the result of prescanning. In such a device, the user must give his direction on whether reading of the original should be executed or not one by one on each original. Furthermore, although Japanese laid-open patent publication Hei 6-139329 discloses an automatic detection of sizes of originals, no reference is made to the judgement on whether reading should be executed or not.